Preamble Sequence Transmission Method, Apparatus, and System

ABSTRACT

Embodiments of the present invention provide a preamble sequence transmission method, apparatus, and system. The method includes: acquiring system information or a physical broadcast channel (PBCH) that is broadcast by a base station, wherein the system information or the PBCH comprises a preset physical random access channel (PRACH) that comprises m preset radio frames and a number of repetition times of a preamble sequence n, which is used for random access, m being a positive integer and wherein 1≦n≦10 m; and sending the preamble sequence to the base station, the preamble sequence being sent at n preset resource locations of the preset PRACH, where the preamble sequence is the format of 1 ms, or the format of 2 ms, or the format of 3 ms.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/793,472, filed on Jul. 7, 2015, which is a continuation ofInternational Application No. PCT/CN2014/070241, filed on Jan. 7, 2014,which claims priority to Chinese Patent Application No.201310005017.1,filed on Jan. 7, 2013. All of the afore-mentioned patent applicationsare hereby incorporated by reference in their entireties.

TECHNICAL FIELD

The present invention relates to the communications field, and inparticular, to a preamble sequence transmission method, apparatus, andsystem.

BACKGROUND

With the continuous development and improvement of communicationssystems, people have increasingly high requirements on communicationquality, that is, they hope to communicate well not only on the groundor in open space, but also in a relatively secluded place such as abasement.

Currently, one radio frame is composed of 10 subframes, and the 10subframes are respectively numbered as subframe 0, subframe 1, subframe2, . . . , and subframe 9. A 10 ms radio frame is used as an example;each subframe of the radio frame is 1 ms, and if a preamble sequence isalso 1 ms, one preamble sequence may be sent within each subframe of theradio frame.

In the prior art, a process in which user equipment randomly gainsaccess to a base station is the first step for the user equipment toimplement uplink synchronization and establish a connection to the basestation. In the process in which the user equipment randomly gainsaccess to the base station, the user equipment randomly selects apreamble sequence that is from the base station and sends the preamblesequence to the base station, so that the base station sends, aftercorrectly matching strength of the received preamble sequence with apreset strength threshold of the base station, a response message torespond to the user equipment, so as to enable the user equipment togain access to the base station.

However, a preamble sequence sent by user equipment located in abasement or other user equipment with a relatively great link loss has arelatively great loss in a transmission process, which accordinglycauses that the base station cannot correctly receive the preamblesequence or that signal strength of the received preamble sequence isrelatively low, and as a result, matching cannot be correctly performedfor the preamble sequence. If no response message is received by theuser equipment from the base station within a preset time, the userequipment selects another random access channel to send a reselectedpreamble sequence to the base station, which makes the user equipmentcontinually send a randomly selected preamble sequence to the basestation; however, the base station still cannot perform matchingcorrectly, thereby causing a decrease in a matching probability of thebase station and a decrease in efficiency of gaining access to the basestation by the user equipment.

SUMMARY

Embodiments of the present invention provide a preamble sequencetransmission method, apparatus, and system, which can enhance signalstrength of a preamble sequence received by a base station, so as toincrease a matching probability of the base station and increaseefficiency of gaining access to the base station by user equipment.

To achieve the foregoing objective, the following technical solutionsare adopted in the embodiments of the present invention.

According to a first aspect, an embodiment of the present inventionprovides a preamble sequence transmission method. The method includesacquiring system information or a physical broadcast channel PBCH thatis broadcast by a base station, where the system information or the PBCHincludes a preset physical random access channel PRACH, the preset PRACHincludes m preset radio frames, and m is a positive integer; determiningthat a quantity of repetition times of a preamble sequence, which isused for random access, at a preset resource location of the presetPRACH is n, where 1≦n≦10 m; and sending, at n preset resource locationsof the preset PRACH, the preamble sequence to the base station.

In a first possible implementation manner of the first aspect, a methodfor the determining that a quantity of repetition times of a preamblesequence, which is used for random access, at a preset resource locationof the preset PRACH is n specifically includes: determining, accordingto the system information or the PBCH, that the quantity of repetitiontimes of the preamble sequence at the preset resource location of thepreset PRACH is n; or, receiving a downlink reference signal sent by thebase station; and determining, according to the downlink referencesignal, that the quantity of repetition times of the preamble sequenceat the preset resource location of the preset PRACH is n; or,determining, according to a pre-formulated wireless communicationprotocol, that the quantity of repetition times of the preamble sequenceat the preset resource location of the preset PRACH is n.

With reference to the first aspect or the first possible implementationmanner of the first aspect, in a second possible implementation manner,the sending, at n preset resource locations of the preset PRACH, thepreamble sequence to the base station includes: sending, within n presetsubframes of the m preset radio frames in the preset PRACH, the preamblesequence to the base station.

With reference to the first aspect or any implementation manner of thefirst possible implementation manner to the second possibleimplementation manner of the first aspect, in a third possibleimplementation manner, after the sending, at n preset resource locationsof the preset PRACH, the preamble sequence to the base station, themethod further includes: if no response message is received from thebase station, sending, at p preset resource locations of the presetPRACH, the preamble sequence to the base station, where p>n.

According to a second aspect, an embodiment of the present inventionfurther provides a preamble sequence transmission method. The methodincludes broadcasting system information or a PBCH, where the systeminformation or the PBCH includes a preset PRACH, the preset PRACHincludes m preset radio frames, and m is a positive integer. The methodalso includes receiving, at n preset resource locations of the presetPRACH, k preamble sequences from user equipment, where the k preamblesequences are sent at the n preset resource locations of the presetPRACH after the user equipment determines that a quantity of repetitiontimes of the preamble sequence, which is used for random access, at apreset resource location of the preset PRACH is n, where 1≦n≦10 m, andk≦n.

In a first possible implementation manner of the second aspect, beforethe receiving, at n preset resource locations of the preset PRACH, kpreamble sequences from user equipment, the method further includes:sending a downlink reference signal, so that the user equipmentdetermines, according to the received downlink reference signal, thatthe quantity of repetition times of the preamble sequence at the presetresource location of the preset PRACH is n.

With reference to the second aspect or the first possible implementationmanner of the second aspect, in a second possible implementation manner,the receiving, at n preset resource locations of the preset PRACH, kpreamble sequences from user equipment includes: receiving, within npreset subframes of the m preset radio frames in the preset PRACH, the kpreamble sequences from the user equipment.

According to a third aspect, an embodiment of the present inventionprovides user equipment. The user equipment includes a first receivingunit, configured to acquire system information or a PBCH that isbroadcast by a base station, where the system information or the PBCHincludes a preset PRACH, the preset PRACH includes m preset radioframes, and m is a positive integer. The user equipment also includes afirst processing unit, configured to determine that a quantity ofrepetition times of a preamble sequence, which is used for randomaccess, at a preset resource location of the preset PRACH is n, where1≦n≦10 m. The user equipment also includes a first sending unit,configured to send, at n preset resource locations of the preset PRACH,the preamble sequence to the base station.

In a first possible implementation manner of the third aspect, the firstprocessing unit is specifically configured to determine, according tothe system information or the PBCH, that the quantity of repetitiontimes of the preamble sequence at the preset resource location of thepreset PRACH is n; or, the first receiving unit is specificallyconfigured to receive a downlink reference signal sent by the basestation, and the first processing unit is specifically configured todetermine, according to the downlink reference signal, that the quantityof repetition times of the preamble sequence at the preset resourcelocation of the preset PRACH is n; or, the first processing unit isspecifically configured to determine, according to a pre-formulatedwireless communication protocol, that the quantity of repetition timesof the preamble sequence at the preset resource location of the presetPRACH is n.

With reference to the third aspect or the first possible implementationmanner of the third aspect, in a second possible implementation manner,the first sending unit is specifically configured to send, within npreset subframes of the m preset radio frames in the preset PRACH, thepreamble sequence to the base station.

With reference to the third aspect or any implementation manner of thefirst possible implementation manner to the second possibleimplementation manner of the third aspect, in a third possibleimplementation manner, the first sending unit is configured to aftersending, at the n preset resource locations of the preset PRACH, thepreamble sequence to the base station, if no response message isreceived by the first receiving unit from the base station, send, at ppreset resource locations of the preset PRACH, the preamble sequence tothe base station, where p>n.

According to a fourth aspect, an embodiment of the present inventionprovides a base station. The base station includes a second sendingunit, configured to broadcast system information or a PBCH, where thesystem information or the PBCH includes a preset PRACH, the preset PRACHincludes m preset radio frames, and m is a positive integer. The basestation also includes a second receiving unit, configured to receive, atn preset resource locations of the preset PRACH, k preamble sequencesfrom user equipment, where the k preamble sequences are sent at the npreset resource locations of the preset PRACH after the user equipmentdetermines that a quantity of repetition times of the preamble sequence,which is used for random access, at a preset resource location of thepreset PRACH is n, where 1≦n≦10 m, and k≦n.

In a first possible implementation manner of the fourth aspect, thesecond sending unit is further configured to send a downlink referencesignal, so that the user equipment determines, according to the receiveddownlink reference signal, that the quantity of repetition times of thepreamble sequence at the preset resource location of the preset PRACH isn.

With reference to the fourth aspect or the first possible implementationmanner of the fourth aspect, in a second possible implementation manner,the second receiving unit is specifically configured to receive, withinn preset subframes of the m preset radio frames in the preset PRACH, thek preamble sequences from the user equipment.

According to a fifth aspect, an embodiment of the present inventionprovides a preamble sequence transmission system, including: the userequipment according to the third aspect and the base station accordingto the fourth aspect.

The embodiments of the present invention provide a preamble sequencetransmission method, apparatus, and system, where the method includes:acquiring system information or a physical broadcast channel PBCH thatis broadcast by a base station, where the system information or the PBCHincludes a preset physical random access channel PRACH, the preset PRACHincludes m preset radio frames, and m is a positive integer; determiningthat a quantity of repetition times of a preamble sequence, which isused for random access, at a preset resource location of the presetPRACH is n, where 1≦n≦10 m; and sending, at n preset resource locationsof the preset PRACH, the preamble sequence to the base station. By usingthis solution, user equipment sends, at the n preset resource locationsof the preset PRACH, the preamble sequence to the base station, that is,the quantity of repetition times of the preamble sequence sent by theuser equipment to the base station increases; therefore, signal strengthof the preamble sequence received by the base station is enhanced, sothat the preamble sequence can be correctly matched, thereby increasinga matching probability of the base station and increasing efficiency ofgaining access to a cell by the user equipment.

BRIEF DESCRIPTION OF THE DRAWINGS

To describe the technical solutions in the embodiments of the presentinvention or in the prior art more clearly, the following brieflyintroduces the accompanying drawings required for describing theembodiments or the prior art. Apparently, the accompanying drawings inthe following description show merely some embodiments of the presentinvention, and a person of ordinary skill in the art may still deriveother drawings from these accompanying drawings without creativeefforts.

FIG. 1 is a schematic structural diagram of a PRACH in the prior art;

FIG. 2 is method flowchart 1 of a preamble sequence transmission methodaccording to an embodiment of the present invention;

FIG. 3 is schematic structural diagram 1 of a preamble sequenceaccording to an embodiment of the present invention;

FIG. 4 is schematic structural diagram 2 of a preamble sequenceaccording to an embodiment of the present invention;

FIG. 5 is schematic structural diagram 3 of a preamble sequenceaccording to an embodiment of the present invention;

FIG. 6 is method flowchart 2 of a preamble sequence transmission methodaccording to an embodiment of the present invention;

FIG. 7 is method flowchart 3 of a preamble sequence transmission methodaccording to an embodiment of the present invention;

FIG. 8 is schematic structural diagram 1 of a preset PRACH according toan embodiment of the present invention;

FIG. 9 is schematic structural diagram 2 of a preset PRACH according toan embodiment of the present invention;

FIG. 10 is schematic structural diagram 3 of a preset PRACH according toan embodiment of the present invention;

FIG. 11 is schematic structural diagram 4 of a preamble sequenceaccording to an embodiment of the present invention;

FIG. 12 is schematic structural diagram 5 of a preamble sequenceaccording to an embodiment of the present invention;

FIG. 13 is schematic structural diagram 1 of user equipment according toan embodiment of the present invention;

FIG. 14 is schematic structural diagram 1 of a base station according toan embodiment of the present invention;

FIG. 15 is schematic structural diagram 2 of a base station according toan embodiment of the present invention;

FIG. 16 is schematic structural diagram 2 of user equipment according toan embodiment of the present invention;

FIG. 17 is schematic structural diagram 3 of a base station according toan embodiment of the present invention;

FIG. 18 is schematic structural diagram 4 of a base station according toan embodiment of the present invention; and

FIG. 19 is a block diagram of a preamble sequence transmission systemaccording to an embodiment of the present invention.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The following clearly describes the technical solutions in theembodiments of the present invention with reference to the accompanyingdrawings in the embodiments of the present invention. Apparently, thedescribed embodiments are merely some but not all of the embodiments ofthe present invention. All other embodiments obtained by a person ofordinary skill in the art based on the embodiments of the presentinvention without creative efforts shall fall within the protectionscope of the present invention.

In the prior art, a process in which user equipment randomly gainsaccess to a base station is the first step for the user equipment toimplement uplink synchronization and establish a connection to the basestation. In the process in which the user equipment gains access to thebase station, the user equipment first receives system information or aPBCH (Physical Broadcast Channel) that is broadcast by the base station,and then transmits, according to the system information or the PBCH andon a selected random access channel, a randomly selected preamblesequence to the base station; and afterward, the user equipment waits toreceive a response message that is from the base station and iscorresponding to the preamble sequence. If no response message isreceived by the user equipment from the base station within a presettime, the user equipment selects another random access channel to resenda reselected preamble sequence to the base station.

It should be noted that the system information or the PBCH that isbroadcast by the base station includes a PRACH (Physical Random AccessChannel) and a preamble sequence available to the user equipment.

A PRACH is shown in FIG. 1. The PRACH may be used to indicate a randomaccess resource that can be used in a process in which user equipmentgains access to a base station. The PRACH shown in FIG. 1 includes two10 ms radio frames, that is, includes twenty 1 ms subframes. Fiveopportunities to send a preamble sequence are set in each frame, and astart point of the preamble sequence is aligned with a start point of acorresponding uplink subframe of the user equipment (it is assumed thata timing advance is 0).

Further, corresponding to the PRACH shown in FIG. 1, in the time domain,the user equipment may send, within a subframe that is set in the PRACH,the preamble sequence once to the base station; in the frequency domain,the preamble sequence occupies six PRBs (Physical Resource Block,physical resource block). It should be noted that one PRB includes onetimeslot in the time domain, and is composed of 12 subcarriers in thefrequency domain. Particularly, each subframe includes two timeslots.

Embodiment 1

This embodiment of the present invention provides a preamble sequencetransmission method, and relates to a user equipment side. As shown inFIG. 2, the method includes:

S101. User equipment acquires system information or a physical broadcastchannel PBCH that is broadcast by a base station, where the systeminformation or the PBCH includes a preset physical random access channelPRACH, the preset PRACH includes m preset radio frames, and m is apositive integer.

In this embodiment of the present invention, once the user equipmententers coverage of the base station, the user equipment can acquire thesystem information or the PBCH that is broadcast by the base station,where the system information or the PBCH includes the preset PRACH andmultiple preamble sequences available to the user equipment. Both thepreset PRACH and the available preamble sequences are necessaryconditions for the user equipment to gain access to the base station.

The preset PRACH includes the m preset radio frames, where m is apositive integer, that is, a value of m may be 1, 2, 3, . . . , and soon, which is not limited in the present invention.

S102. The user equipment determines that a quantity of repetition timesof a preamble sequence, which is used for random access, at a presetresource location of the preset PRACH is n, where 1≦n≦10 m.

The user equipment may randomly select, from the multiple preamblesequences according to the acquired system information or PBCH that isfrom the base station, one preamble sequence used for random access. Inaddition, the user equipment may determine, according to a preset rule,that the quantity of repetition times of the preamble sequence, which isused for random access by the user equipment, at the preset resourcelocation of the preset PRACH is n, where 1≦n≦10 m.

A signal format of the preamble sequence is shown in FIG. 3, andincludes a CP (Cyclic Prefix), a preamble, and a protection time. In anFDD (Frequency Division Duplex) system, three signal formats of preamblesequences are defined, and are respectively signal formats of a 1 mspreamble sequence, a 2 ms preamble sequence, and a 3 ms preamblesequence. FIG. 3 shows a signal format of a 1 ms preamble sequence. Inthe 1 ms preamble sequence, a length of a preamble is 0.8 ms, and alength of a CP and a length of a protection time are both 0.1 ms. FIG. 4shows a signal format of a 2 ms preamble sequence. In the 2 ms preamblesequence, a length of a preamble is 1.6 ms, and a length of a CP and alength of a protection time are both 0.2 ms. FIG. 5 shows is a signalformat of a 3 ms preamble sequence. In the 3 ms preamble sequence, alength of a preamble is 1.6 ms, and a length of a CP and a length of aprotection time are both 0.7 ms.

It should be noted that different preamble sequences are applied todifferent scenarios, and may be selected according to different basestation coverage. Generally, a greater length of a CP indicates that apreamble sequence can be applicable to a case in which a round-tripdelay is longer, that is, larger base station coverage can be supported.The length of a preamble mainly affects quality of receiving a preamblesequence by the base station, and a longer preamble means that the basestation can obtain better received quality and therefore obtains betterdemodulation performance.

Particularly, the signal format of the preamble sequence in thisembodiment of the present invention may be 1 ms, 2 ms, 3 ms, or anyother preamble sequence that meets a design requirement, which is notlimited in the present invention.

Exemplarily, that the preamble sequence provided in this embodiment ofthe present invention is 1 ms is used as an example. If the preset PRACHincludes two preset 10 ms radio frames, the preamble sequence may besent once within each subframe of each preset 10 ms radio frame. In thiscase, a quantity of repetition times of the preamble sequence sent bythe user equipment to the base station within the two preset 10 ms radioframes may be 20 at most. Preferably, if a quantity of repetition timesof the preamble sequence sent by the user equipment to the base stationis 2^(x), where x is a positive integer, and 2≦2^(x)≦20, the quantity ofrepetition times of the preamble sequence sent by the user equipment tothe base station within two 10 ms radio frames may be 2¹ (that is, two),2² (that is, four), 2³ (that is, eight), or 2⁴ (that is, 16). Similarly,if the preset PRACH includes four preset 10 ms radio frames, preferably,the quantity of repetition times of the preamble sequence sent by theuser equipment to the base station may be 2⁵ (that is, 32) at most.

Certainly, if the preamble sequence provided in this embodiment of thepresent invention is 2 ms, within the two preset 10 ms radio frames inthe preset PRACH, the user equipment may send the preamble sequence tothe base station once within each two subframes; that is, within the tworadio frames, the quantity of repetition times of the preamble sequencesent by the user equipment to the base station may be 10 at most.Preferably, the quantity of repetition times of the preamble sequencesent by the user equipment to the base station may be 2, 4, or 8.

S103. The user equipment sends, at n preset resource locations of thepreset PRACH, the preamble sequence to the base station.

The user equipment may send, at the n preset resource locations of thepreset PRACH, the preamble sequence to the base station, so that thebase station returns, after adding up and performing matching for allreceived same preamble sequences, a response message corresponding tothe preamble sequence, thereby enabling the user equipment to gainaccess to the base station.

This embodiment of the present invention provides a preamble sequencetransmission method, and relates to a base station side. As shown inFIG. 6, the method includes:

S201. A base station broadcasts system information or a PBCH, where thesystem information or the PBCH includes a preset PRACH, the preset PRACHincludes m preset radio frames, and m is a positive integer.

The base station periodically broadcasts the system information or thePBCH within coverage of the base station, where the system informationor the PBCH includes the preset PRACH and multiple preamble sequencesavailable to the user equipment, the preset PRACH includes the m presetradio frames, and m is a positive integer, that is, a value of m may be1, 2, 3, . . . , and so on, which is not limited in the presentinvention.

S202. The base station receives, at n preset resource locations of thepreset PRACH, k preamble sequences from user equipment, where 1≦n≦10 m,and k≦n.

The base station receives, at the n preset resource locations of thepreset PRACH, the k preamble sequences from the user equipment, wherethe k preamble sequences are selected by the user equipment according tothe acquired system information or PBCH that is broadcast by the basestation and from the multiple preamble sequences that are available tothe user equipment and are broadcast by the base station; and the kpreamble sequences are sent at the n preset resource locations of thepreset PRACH according to a preset rule after it is determined that aquantity of repetition times of the preamble sequence, which is used forrandom access, at a preset resource location of the preset PRACH is n,where 1≦n≦10 m, and k≦n.

Particularly, the signal format of the preamble sequence provided inthis embodiment of the present invention may be 1 ms, 2 ms, 3 ms, or anyother preamble sequence that meets a requirement, which is not limitedin the present invention.

It should be noted that, in this embodiment of the present invention,the provided preamble sequence transmission method on the user equipmentside is corresponding to the provided preamble sequence transmissionmethod on the base station side; that is, the user equipment sends thepreamble sequence at the n preset resource locations of the presetPRACH, and the base station receives the preamble sequence at the npreset resource locations of the preset PRACH.

It may be understood by a person skilled in the art that, a phenomenonof a transmission failure may exist in a preamble sequence transmissionprocess; therefore, a quantity of preamble sequences received by thebase station at the n preset resource locations of the preset PRACH isk, where k n.

In this embodiment of the present invention, user equipment sends, at npreset resource locations of a preset PRACH, a preamble sequence to abase station, that is, a quantity of repetition times of the preamblesequence sent by the user equipment to the base station increases;therefore, signal strength of the preamble sequence received by the basestation is enhanced, so that the preamble sequence can be correctlymatched, thereby increasing a matching probability of the base stationand increasing efficiency of gaining access to a cell by the userequipment.

Exemplarily, in the present invention, it is assumed that m=2, that is,a preset PRACH includes two preset radio frames, and a preamble sequenceis a 1 ms preamble sequence. This embodiment of the present inventionfurther provides a preamble sequence transmission method. As shown inFIG. 7, the method includes:

S301. A base station broadcasts system information or a PBCH, where thesystem information or the PBCH includes a preset PRACH and multiplepreamble sequences, and the preset PRACH includes two preset radioframes.

The base station periodically broadcasts the system information or thePBCH within coverage of the base station, where the system informationor the PBCH includes the preset PRACH and the multiple preamblesequences available to user equipment, and the preset PRACH includes thetwo preset radio frames. Both the preset PRACH and the availablepreamble sequences are necessary conditions for the user equipment togain access to the base station.

S302. User equipment acquires the system information or the PBCH, andselects, from the multiple preamble sequences according to the systeminformation or the PBCH, one preamble sequence used for random access.

The user equipment acquires the system information or the PBCH that isbroadcast by the base station, and randomly selects, from the multiplepreamble sequences available to the user equipment and according to theacquired system information or PBCH, the preamble sequence used forrandom access.

S303. The user equipment determines that a quantity of repetition timesof the preamble sequence, which is used for random access, at a presetresource location of the preset PRACH is n, where 1≦n≦20.

Exemplarily, it is assumed that m=2, and therefore, a value of n may be1, 2, 3, 4, . . . , or 20; that is, if the preset PRACH includes twopreset radio frames, the quantity of repetition times of the preamblesequence sent by the user equipment to the base station may be 1, 2, 3,4, . . . , or 20. Preferably, the quantity of repetition times of thepreamble sequence sent by the user equipment to the base station may be2, 4, 8, or 16. Specifically, the quantity of repetition times of thepreamble sequence sent by the user equipment to the base station may beadaptively adjusted according to an actual requirement and design, andis not limited in the present invention.

In an LTE (Long Term Evolution) system, each radio frame is generally 10ms.

Specifically, a method for determining, by the user equipment accordingto a preset rule, that the quantity of repetition times of the preamblesequence, which is used for random access, at the preset resourcelocation of the preset PRACH is n may be any one of the following.

(1) The user equipment determines, according to the system informationor the PBCH, that the quantity of repetition times of the preamblesequence at the preset resource location of the preset PRACH is n.

The user equipment may learn, from the system information or the PBCHthat is broadcast by the base station and is received downlink, thequantity of repetition times of the preamble sequence, which is sent tothe base station, at the preset resource location of the preset PRACH isn.

It should be noted that, in this embodiment of the present invention,downlink may be defined as a process in which the base station sends asignal to the user equipment; and oppositely, uplink may be defined as aprocess in which the user equipment sends a signal to the base station.

(2) The user equipment receives a downlink reference signal sent by thebase station, and determines, according to the downlink referencesignal, that the quantity of repetition times of the preamble sequenceat the preset resource location of the preset PRACH is n.

The user equipment may measure its own link loss according to thereceived downlink reference signal sent by the base station, anddifferent link loss levels correspond to different quantities ofrepetition times of the preamble sequence at the preset resourcelocation of the preset PRACH.

Exemplarily, that the preamble sequence provided in this embodiment ofthe present invention is 1 ms is used as an example. It is assumed thatthe preset PRACH includes two preset 10 ms radio frames; therefore, thepreamble sequence may be sent once within each subframe of each 10 msradio frame. In this case, a quantity of repetition times of thepreamble sequence sent by the user equipment to the base station withinthe two preset 10 ms radio frames may be 20 at most. Preferably, if aquantity of repetition times of the preamble sequence sent by the userequipment to the base station is 2 ^(x), where x is a positive integer,and 2≦2 ^(x)≦20, the quantity of repetition times of the preamblesequence sent by the user equipment to the base station within twopreset 10 ms radio frames may be 2¹ (that is, two), 2² (that is, four),2³ (that is, eight), or 2⁴ (that is, 16).

Further, is the setting is performed according to the preferred quantityof repetition times of the preamble sequence sent by the user equipmentto the base station within the two preset 10 ms radio frames. If thelink loss is less than 50 dB, a corresponding quantity of repetitiontimes of the preamble sequence is four; if the link loss is greater thanor equal to 50 dB, and less than or equal to 100 dB, a correspondingquantity of repetition times of the preamble sequence is eight; if thelink loss is greater than or equal to 100 dB, a corresponding quantityof repetition times of the preamble sequence is 16.

(3) The user equipment may determine, according to a pre-formulatedwireless communication protocol, that the quantity of repetition timesof the preamble sequence at the preset resource location of the presetPRACH is n.

The user equipment may learn, from the pre-formulated wirelesscommunication protocol, that the quantity of repetition times of thepreamble sequence, which is sent to the base station, at the presetresource location of the preset PRACH is n. Specifically, whenformulating the wireless communication protocol, operators set, by meansof a mutual agreement, that the quantity of repetition times of thepreamble sequence, which is sent by the user equipment to the basestation, at the preset resource location of the preset PRACH is n.

S304. The user equipment sends, at n preset resource locations of thepreset PRACH, the preamble sequence to the base station.

The user equipment may send, at the n preset resource locations of thepreset

PRACH, the preamble sequence to the base station.

Further, the user equipment may send, at n preset resource locations oftwo preset radio frames in the preset PRACH, the preamble sequence tothe base station.

Further, the user equipment may send, within n preset subframes of thetwo preset radio frames in the preset PRACH, the preamble sequence tothe base station.

It should be noted that the n preset resource locations of the presetPRACH provided in this embodiment of the present invention include the npreset resource locations of the two preset radio frames in the presetPRACH.

Further, the n preset resource locations of the two preset radio framesin the preset PRACH provided in this embodiment of the present inventionspecifically include the n preset subframes of the two preset radioframes in the preset PRACH.

Exemplarily, as shown in FIG. 8, FIG. 8 is a schematic structuraldiagram of a preset PRACH according to an embodiment of the presentinvention, where the preset PRACH includes two consecutive preset radioframes.

If n=2, that is, the user equipment sends, at two preset resourcelocations of the two preset radio frames, the preamble sequence to thebase station, as shown in FIG. 8, the user equipment may separatelysend, in subframe 1 of a first frame and subframe 5 of the first frame,the preamble sequence once to the base station; or the user equipmentmay separately send, in subframe 9 of a first frame and subframe 1 of asecond frame, the preamble sequence once to the base station; or theuser equipment may separately send, in subframe 5 of a second frame andsubframe 9 of the second frame, the preamble sequence once to the basestation.

If n=4, that is, the user equipment sends, at four preset resourcelocations of the two preset radio frames, the preamble sequence to thebase station, as shown in FIG. 8, the user equipment may separatelysend, in subframe 3 of a first frame, subframe 7 of the first frame,subframe 3 of a second frame, and subframe 7 of the second frame, thepreamble sequence once to the base station.

Exemplarily, as shown in FIG. 9, FIG. 9 is a schematic structuraldiagram of another preset PRACH according to an embodiment of thepresent invention, where the another preset PRACH includes twoconsecutive preset radio frames.

If n=2, that is, the user equipment sends, at two preset resourcelocations of the two preset radio frames, the preamble sequence to thebase station, as shown in FIG. 9, the user equipment may separatelysend, in subframe 9 of a first frame and subframe 1 of a second frame,the preamble sequence once to the base station.

If n=4, that is, the user equipment sends, at four preset resourcelocations of the two preset radio frames, the preamble sequence to thebase station, as shown in FIG. 9, the user equipment may separatelysend, in subframe 1 of a first frame, subframe 3 of the first frame,subframe 5 of the first frame, and subframe 7 of the first frame, thepreamble sequence once to the base station; or the user equipment mayseparately send, in subframe 3 of a second frame, subframe 5 of thesecond frame, subframe 7 of the second frame, and subframe 9 of thesecond frame, the preamble sequence once to the base station.

It should be noted that the foregoing schematic structural diagrams ofthe preset PRACH are only for exemplary illustration of this embodimentof the present invention. A person of ordinary skill in the art mayunderstand that the preset PRACH provided in the present invention, thatis, the preset resource location of the preset PRACH provided in thepresent invention may be adaptively adjusted according to an actualrequirement, and is not limited in the present invention.

S305. The base station adds up signal strength of k received preamblesequences, where k≦n.

The base station adds up the signal strength of the k received preamblesequences after the base station receives, at the n preset resourcelocations of the preset PRACH, the k preamble sequences from the userequipment, where k≦n.

S306. The base station performs comparison between added-up signalstrength of the k preamble sequences and a preset strength threshold.

The base station performs comparison between the added-up signalstrength of the k preamble sequences and the preset strength threshold,that is, the base station performs matching between the added-up signalstrength of the k preamble sequences and the preset strength threshold.

S307. If the added-up signal strength of the k preamble sequences isgreater than or equal to the preset strength threshold, the base stationreturns a response message corresponding to the k preamble sequences.

If the added-up signal strength of the k preamble sequences is greaterthan or equal to the preset strength threshold, that is, the signalstrength obtained by the base station by adding up the k receivedpreamble sequences can match the preset strength threshold, the basestation returns the response message corresponding to the k preamblesequences to the user equipment.

A person of ordinary skill in the art may understand that, that the basestation adds up the signal strength of the k received preamble sequencesmay be that the base station adds up the signal strength of the kreceived preamble sequences, so as to obtain total signal strength ofthe k received preamble sequences. The base station performs comparisonbetween the total signal strength and the preset strength threshold,that is, the base station performs matching between the total signalstrength and the preset strength threshold; if the total signal strengthis greater than or equal to the preset strength threshold, that is, thetotal signal strength can correctly match the preset strength threshold,the base station sends the response message corresponding to the kpreamble sequences to the user equipment, so that the user equipmentgains access to the base station.

It should be noted that the quantity of repetition times proposed ineach of the foregoing three methods for determining, by the userequipment, the quantity of repetition times of the preamble sequence,which is used for random access, at the preset resource location of thepreset PRACH is a maximum quantity of repetition times pre-formulatedaccording to a maximum link loss of the user equipment, so as toimplement that, after the user equipment sends the selected preamblesequence at the n preset resource locations of the preset PRACH, thebase station can correctly perform matching for the k received preamblesequences and return a corresponding response message to the userequipment, thereby increasing a matching probability of the base stationand increasing efficiency of gaining access to the base station by theuser equipment.

In another implementation manner of the preamble sequence transmissionmethod provided in this embodiment of the present invention, after theuser equipment send, at the n preset resource locations of the presetPRACH, the preamble sequence to the base station according to the presetPRACH, if no response message that is from the base station and iscorresponding to the preamble sequence is detected by the user equipmentwithin a preset time, the user equipment may send, at p preset resourcelocations of the preset PRACH, the preamble sequence to the basestation, where p>n.

A person of ordinary skill in the art may understand that, after theuser equipment sends, at the n preset resource locations of the presetPRACH, the preamble sequence to the base station, if no correspondingresponse message is received by the user equipment from the base stationwithin a preset time, the user equipment may send, at p preset resourcelocations of the preset PRACH, the preamble sequence to the basestation, where p>n.

It should be noted that the foregoing n preset resource locations of thepreset PRACH may be specifically n preset subframes of two preset radioframes in the preset PRACH, where the n preset subframes are presetsubframes in which the preamble sequence is repeatedly sent.Correspondingly, the foregoing p preset resource locations of the presetPRACH may also be specifically p preset subframes of the two presetradio frames in the preset PRACH, where the p preset subframes arepreset subframes in which the preamble sequence is repeatedly sent. Then preset subframes and the p preset subframes may be same subframes ormay be different subframes.

Particularly, when one subframe includes, in the frequency domain, twoavailable resource locations that are used to send the preamblesequence, two resource locations in a same subframe may be respectivelypreset to a location for n-times repetition of the preamble sequence anda location for p-times repetition of the preamble sequence; and in thiscase, a subframe in which the preamble sequence repeats n times and asubframe in which the preamble sequence repeats p times are a samesubframe. Correspondingly, if one subframe includes only one availableresource location used to send the preamble sequence, the availableresource location may be preset to a location for n-times repetition ofthe preamble sequence or a location for p-times repetition of thepreamble sequence; and in this case, a subframe in which the preamblesequence repeats n times and a subframe in which the preamble sequencerepeats p times are different subframes.

Specifically, as shown in FIG. 10, after the user equipment separatelysends, in subframe 1 of a first frame and subframe 5 of the first frame,the preamble sequence once to the base station, if no response messagethat is from the base station and is corresponding to the preamblesequence is received, the user equipment may separately send, insubframe 3 of a second frame, subframe 5 of the second frame, subframe 7of the second frame, and subframe 9 of the second frame, the preamblesequence once to the base station.

It should be noted that the foregoing schematic structural diagram ofthe preset PRACH is only for exemplary illustration of this embodimentof the present invention. A person of ordinary skill in the art mayunderstand that the preset PRACH provided in the present invention, thatis, the preset resource location of the preset PRACH provided in thepresent invention may be adaptively adjusted according to an actualrequirement, and is not limited in the present invention.

Further, the described preamble sequence transmission method and anotherimplementation manner of the preamble sequence transmission methodprovided in this embodiment of the present invention are both applicableto an FDD system and a TDD (Time Division Duplex, time division duplex)system.

This embodiment of the present invention further provides anotherimplementation manner of the preamble sequence transmission method. Inthe implementation manner, a signal format of the preamble sequence ischanged, that is, concatenation is performed on preamble sequences inthe prior art to form a new preamble sequence, and the preset resourcelocations of the preset PRACH are preset to consecutive subframes tosend the new preamble sequence.

Exemplarily, FIG. 11 shows a new preamble sequence formed afterconcatenation is performed on two 2 ms preamble sequences in the priorart. It can be learned from FIG. 11 that a length of a CP and a lengthof a protection time in each 2 ms preamble sequence of the new preamblesequence remain unchanged, that is, a radius of base station coveragesupported by the new preamble sequence is the same as a radius of basestation coverage supported by the 2 ms preamble sequence.

Particularly, if the preset PRACH provided in this embodiment of thepresent invention includes two preset 10 ms radio frames, for a 1 mspreamble sequence, one opportunity to send the 1 ms preamble sequencemay be preset in each subframe of each preset 10 ms radio frame; for a 2ms preamble sequence, one opportunity to send the 2 ms preamble sequencemay be preset in each two consecutive subframes of each preset 10 msradio frame. In that way, for the new preamble sequence formed afterconcatenation is performed on the two 2 ms preamble sequences, oneopportunity to send the new preamble sequence may be preset in each fourconsecutive subframes of each preset 10 ms radio frame.

Exemplarily, FIG. 12 shows a new preamble sequence formed afterconcatenation is performed on seven 1 ms preamble sequences in the priorart. It can be learned from FIG. 12 that a preamble, a CP, and aprotection time of the preamble sequence are all seven times a preamble,a CP, and a protection time of a 1 ms preamble sequence; that is,because the CP and the protection time increase, a radius of basestation coverage supported by the new preamble sequence is greater thana radius of base station coverage supported by the 1 ms preamblesequence.

It should be noted that a signal format of the new preamble sequenceneeds to be defined in the foregoing another implementation manner ofthe preamble sequence transmission method, and the preset resourcelocations of the preset PRACH need to be preset to consecutive subframesto send the new preamble sequence. Particularly, the implementationmanner is only applicable to an FDD system.

According to the preamble sequence transmission method provided in thisembodiment of the present invention, system information or a physicalbroadcast channel PBCH that is broadcast by a base station is acquired,where the system information or the PBCH includes a preset physicalrandom access channel PRACH, the preset PRACH includes m preset radioframes, and m is a positive integer; it is determined that a quantity ofrepetition times of a preamble sequence, which is used for randomaccess, at a preset resource location of the preset PRACH is n, where1≦n≦10 m; and the preamble sequence is sent to the base station at npreset resource locations of the preset PRACH. By using this solution,user equipment sends, at the n preset resource locations of the presetPRACH, the preamble sequence to the base station, that is, the quantityof repetition times of the preamble sequence sent by the user equipmentto the base station increases; therefore, signal strength of thepreamble sequence received by the base station is enhanced, so that thepreamble sequence can be correctly matched, thereby increasing amatching probability of the base station and increasing efficiency ofgaining access to a cell by the user equipment.

Embodiment 2

As shown in FIG. 13, this embodiment of the present invention providesuser equipment 4, including: a first receiving unit 40, configured toacquire system information or a PBCH that is broadcast by a basestation, where the system information or the PBCH includes a presetPRACH, the preset PRACH includes m preset radio frames, and m is apositive integer; a first processing unit 41, configured to determinethat a quantity of repetition times of a preamble sequence, which isused for random access, at a preset resource location of the presetPRACH is n, where 1≦n≦10 m; and a first sending unit 42, configured tosend, at n preset resource locations of the preset PRACH, the preamblesequence to the base station.

The first processing unit 41 is specifically configured to determine,according to the system information or the PBCH, that the quantity ofrepetition times of the preamble sequence at the preset resourcelocation of the preset PRACH is n; or the first receiving unit 40 isspecifically configured to receive a downlink reference signal sent bythe base station, and the first processing unit 41 is specificallyconfigured to determine, according to the downlink reference signal,that the quantity of repetition times of the preamble sequence at thepreset resource location of the preset PRACH is n; or the firstprocessing unit 41 is specifically configured to determine, according toa pre-formulated wireless communication protocol, that the quantity ofrepetition times of the preamble sequence at the preset resourcelocation of the preset PRACH is n.

The first processing unit 41 is further configured to select, frommultiple available preamble sequences according to the systeminformation or the PBCH, one preamble sequence used for random access.

Further, the first sending unit 42 is specifically configured to send,at the n preset resource locations of the m preset radio frames in thepreset PRACH, the preamble sequence to the base station.

Further, the first sending unit 42 is specifically configured to send,within n preset subframes of the m preset radio frames in the presetPRACH, the preamble sequence to the base station.

Referring to FIG. 8, a 1 ms preamble sequence and that the preset PRACHincludes two consecutive preset 10 ms radio frames are used as anexample in this embodiment of the present invention. Corresponding tothe preset PRACH provided in this embodiment of the present invention,if the quantity of repetition times of the preamble sequence sent by theuser equipment to the base station is two, the first sending unit 42 isspecifically configured to separately send, in subframe 1 of a firstframe and subframe 5 of the first frame, the preamble sequence once tothe base station; or the first sending unit 42 separately sends, insubframe 9 of the first frame and subframe 1 of a second frame, thepreamble sequence once to the base station; or the first sending unit 42separately sends, in subframe 5 of the second frame and subframe 9 ofthe second frame, the preamble sequence once to the base station.

Alternatively, if the quantity of repetition times of the preamblesequence sent by the user equipment to the base station is four, thefirst sending unit 42 is specifically configured to separately send, insubframe 3 of the first frame, subframe 7 of the first frame, subframe 3of the second frame, and subframe 7 of the second frame, the preamblesequence once to the base station.

Referring to FIG. 9, a 1 ms preamble sequence and that the preset PRACHincludes two consecutive preset 10 ms radio frames are used as anexample in this embodiment of the present invention. Corresponding toanother preset PRACH provided in this embodiment of the presentinvention, if the quantity of repetition times of the preamble sequencesent by the user equipment to the base station is two, the first sendingunit 42 is specifically configured to separately send, in subframe 9 ofa first frame and subframe 1 of a second frame, the preamble sequenceonce to the base station.

Alternatively, if the quantity of repetition times of the preamblesequence sent by the user equipment to the base station is four, thefirst sending unit 42 is specifically configured to separately send, insubframe 1 of a first frame, subframe 3 of the first frame, subframe 5of the first frame, and subframe 7 of the first frame, the preamblesequence once to the base station; or the first sending unit 42separately sends, in subframe 3 of a second frame, subframe 5 of thesecond frame, subframe 7 of the second frame, and subframe 9 of thesecond frame, the preamble sequence once to the base station.

It should be noted that the foregoing schematic structural diagrams ofthe preset PRACH are only for exemplary illustration of this embodimentof the present invention. A person of ordinary skill in the art mayunderstand that the preset PRACH provided in the present invention, thatis, the preset resource location of the preset PRACH provided in thepresent invention may be adaptively adjusted according to an actualrequirement, and is not limited in the present invention.

This embodiment of the present invention further provides anotherimplementation manner of the user equipment, where the implementationmanner includes that: the first sending unit 42 is configured to aftersending, at the n preset resource locations of the preset PRACH, thepreamble sequence to the base station, if no response message isreceived by the first receiving unit 40 from the base station, send, atp preset resource locations of the preset PRACH, the preamble sequenceto the base station, where p>n.

Corresponding to the another implementation manner of the user equipmentprovided in this embodiment of the present invention, the first sendingunit 42 is configured to after separately sending, in subframe 1 of afirst frame and subframe 5 of the first frame, the preamble sequenceonce to the base station, if no response message that is from the basestation and is corresponding to the preamble sequence is received by thefirst receiving unit 40, separately send, in subframe 3 of a secondframe, subframe 5 of the second frame, subframe 7 of the second frame,and subframe 9 of the second frame, the preamble sequence once to thebase station.

According to the user equipment provided in this embodiment of thepresent invention, system information or a physical broadcast channelPBCH that is broadcast by a base station is acquired, where the systeminformation or the PBCH includes a preset physical random access channelPRACH, the preset PRACH includes m preset radio frames, and m is apositive integer; it is determined that a quantity of repetition timesof a preamble sequence, which is used for random access, at a presetresource location of the preset PRACH is n, where 1 ≦n≦10 m; and thepreamble sequence is sent to the base station at n preset resourcelocations of the preset PRACH. By using this solution, the userequipment sends, at the n preset resource locations of the preset PRACH,the preamble sequence to the base station, that is, the quantity ofrepetition times of the preamble sequence sent by the user equipment tothe base station increases; therefore, signal strength of the preamblesequence received by the base station is enhanced, so that the preamblesequence can be correctly matched, thereby increasing a matchingprobability of the base station and increasing efficiency of gainingaccess to a cell by the user equipment.

As shown in FIG. 14, this embodiment of the present invention provides abase station 5, including: a second sending unit 50, configured tobroadcast system information or a PBCH, where the system information orthe PBCH includes a preset PRACH, the preset PRACH includes m presetradio frames, and m is a positive integer; and a second receiving unit51, configured to receive, at n preset resource locations of the presetPRACH, k preamble sequences from user equipment, where the k preamblesequences are sent at the n preset resource locations of the presetPRACH after the user equipment determines that a quantity of repetitiontimes of the preamble sequence, which is used for random access, at apreset resource location of the preset PRACH is n, where 1≦n≦10 m, andk≦n.

Further, the second sending unit 50 is further configured to send adownlink reference signal, so that the user equipment determines,according to the received downlink reference signal, that the quantityof repetition times of the preamble sequence at the preset resourcelocation of the preset PRACH is n.

Further, the second receiving unit 51 is specifically configured toreceive, at the n preset resource locations of the m preset radio framesin the preset PRACH, the k preamble sequences from the user equipment.

Further, the second receiving unit 51 is specifically configured toreceive, within n preset subframes of the m preset radio frames in thepreset PRACH, the k preamble sequences from the user equipment.

As shown in FIG. 15, the base station 5 provided in this embodiment ofthe present invention further includes: a second processing unit 52,configured to: add up signal strength of the k preamble sequencesreceived by the second receiving unit 51, and perform comparison betweenadded-up signal strength of the k preamble sequences and a presetstrength threshold.

Further, the second sending unit 50 is further configured to: if thesignal strength obtained by the second processing unit 52 by adding upthe k received preamble sequences is greater than or equal to the presetstrength threshold, return a response message corresponding to the kpreamble sequences to the user equipment.

According to the base station provided in this embodiment of the presentinvention, system information or a PBCH is broadcast, where the systeminformation or the PBCH includes a preset PRACH, the preset PRACHincludes m preset radio frames, and m is a positive integer; k preamblesequences are received from user equipment at n preset resourcelocations of the preset PRACH, where the k preamble sequences are sentat the n preset resource locations of the preset PRACH after the userequipment determines that a quantity of repetition times of the preamblesequence, which is used for random access, at a preset resource locationof the preset PRACH is n. By using this solution, the user equipmentsends, at the n preset resource locations of the preset PRACH, thepreamble sequence to the base station, that is, the quantity ofrepetition times of the preamble sequence sent by the user equipment tothe base station increases; therefore, signal strength of the preamblesequence received by the base station is enhanced, so that the preamblesequence can be correctly matched, thereby increasing a matchingprobability of the base station and increasing efficiency of gainingaccess to a cell by the user equipment.

Embodiment 3

As shown in FIG. 16, this embodiment of the present invention providesuser equipment 4, including: a first receiver 44, configured to acquiresystem information or a PBCH that is broadcast by a base station, wherethe system information or the PBCH includes a preset PRACH, the presetPRACH includes m preset radio frames, and m is a positive integer; afirst processor 45, configured to determine that a quantity ofrepetition times of a preamble sequence, which is used for randomaccess, at a preset resource location of the preset PRACH is n, where1≦n≦10 m; and a first transmitter 46, configured to send, at n presetresource locations of the preset PRACH, the preamble sequence to thebase station.

The first processor 45 is specifically configured to determine,according to the system information or the PBCH, that the quantity ofrepetition times of the preamble sequence at the preset resourcelocation of the preset PRACH is n.

Alternatively, the first receiver 44 is specifically configured toreceive a downlink reference signal sent by the base station, and thefirst processor 45 is specifically configured to determine, according tothe downlink reference signal, that the quantity of repetition times ofthe preamble sequence at the preset resource location of the presetPRACH is n.

Alternatively, the first processor 45 is specifically configured todetermine, according to a pre-formulated wireless communicationprotocol, that the quantity of repetition times of the preamble sequenceat the preset resource location of the preset PRACH is n.

The first processor 45 is further configured to select, from multipleavailable preamble sequences according to the system information or thePBCH, one preamble sequence used for random access.

Further, the first transmitter 46 is specifically configured to send, atthe n preset resource locations of the m preset radio frames in thepreset PRACH, the preamble sequence to the base station.

Further, the first transmitter 46 is specifically configured to send,within n preset subframes of the m preset radio frames in the presetPRACH, the preamble sequence to the base station.

Referring to FIG. 8, a 1 ms preamble sequence and that the preset PRACHincludes two consecutive preset 10 ms radio frames are used as anexample in this embodiment of the present invention. Corresponding tothe preset PRACH provided in this embodiment of the present invention,if the quantity of repetition times of the preamble sequence sent by theuser equipment to the base station is two, the first transmitter 46 isspecifically configured to: separately send, in subframe 1 of a firstframe and subframe 5 of the first frame, the preamble sequence once tothe base station; or separately send, in subframe 9 of a first frame andsubframe 1 of a second frame, the preamble sequence once to the basestation; or separately send, in subframe 5 of a second frame andsubframe 9 of the second frame, the preamble sequence once to the basestation.

Alternatively, if the quantity of repetition times of the preamblesequence sent by the user equipment to the base station is four, thefirst transmitter 46 is specifically configured to separately send, insubframe 3 of a first frame, subframe 7 of the first frame, subframe 3of a second frame, and subframe 7 of the second frame, the preamblesequence once to the base station.

Referring to FIG. 9, a 1 ms preamble sequence and that the preset PRACHincludes two consecutive preset 10 ms radio frames are used as anexample in this embodiment of the present invention. Corresponding toanother preset PRACH provided in this embodiment of the presentinvention, if the quantity of repetition times of the preamble sequencesent by the user equipment to the base station is two, the firsttransmitter 46 is specifically configured to separately send, insubframe 9 of a first frame and subframe 1 of a second frame, thepreamble sequence once to the base station.

Alternatively, if the quantity of repetition times of the preamblesequence sent by the user equipment to the base station is four, thefirst transmitter 46 is specifically configured to: separately send, insubframe 1 of a first frame, subframe 3 of the first frame, subframe 5of the first frame, and subframe 7 of the first frame, the preamblesequence once to the base station; or separately send, in subframe 3 ofa second frame, subframe 5 of the second frame, subframe 7 of the secondframe, and subframe 9 of the second frame, the preamble sequence once tothe base station.

It should be noted that the foregoing schematic structural diagrams ofthe preset PRACH are only for exemplary illustration of this embodimentof the present invention. A person of ordinary skill in the art mayunderstand that the preset PRACH provided in the present invention, thatis, the preset resource location of the preset PRACH provided in thepresent invention may be adaptively adjusted according to an actualrequirement, and is not limited in the present invention.

This embodiment of the present invention further provides anotherimplementation manner of the user equipment, where the implementationmanner includes that: the first transmitter 46 is configured to aftersending, at the n preset resource locations of the preset PRACH, thepreamble sequence to the base station, if no response message isreceived by the first receiver 44 from the base station, send, at ppreset resource locations of the preset PRACH, the preamble sequence tothe base station, where p>n.

Corresponding to the another implementation manner of the preamblesequence transmission method provided in this embodiment of the presentinvention, the first transmitter 46 is configured to after separatelysending, in subframe 1 of a first frame and subframe 5 of the firstframe, the preamble sequence once to the base station, if no responsemessage that is from the base station and is corresponding to thepreamble sequence is received by the first receiver 44, separately send,in subframe 3 of a second frame, subframe 5 of the second frame,subframe 7 of the second frame, and subframe 9 of the second frame, thepreamble sequence once to the base station.

According to the user equipment provided in this embodiment of thepresent invention, system information or a physical broadcast channelPBCH that is broadcast by a base station is acquired, where the systeminformation or the PBCH includes a preset physical random access channelPRACH, the preset PRACH includes m preset radio frames, and m is apositive integer; it is determined that a quantity of repetition timesof a preamble sequence, which is used for random access, at a presetresource location of the preset PRACH is n, where 1 ≦n≦10 m; and thepreamble sequence is sent to the base station at n preset resourcelocations of the preset PRACH. By using this solution, the userequipment sends, at the n preset resource locations of the preset PRACH,the preamble sequence to the base station, that is, the quantity ofrepetition times of the preamble sequence sent by the user equipment tothe base station increases; therefore, signal strength of the preamblesequence received by the base station is enhanced, so that the preamblesequence can be correctly matched, thereby increasing a matchingprobability of the base station and increasing efficiency of gainingaccess to a cell by the user equipment.

As shown in FIG. 17, this embodiment of the present invention provides abase station 5, including: a second transmitter 53, configured tobroadcast system information or a PBCH, where the system information orthe PBCH includes a preset PRACH, the preset PRACH includes m presetradio frames, and m is a positive integer; and a second receiver 54,configured to receive, at n preset resource locations of the presetPRACH, k preamble sequences from user equipment, where the k preamblesequences are sent at the n preset resource locations of the presetPRACH after the user equipment determines that a quantity of repetitiontimes of the preamble sequence, which is used for random access, at apreset resource location of the preset PRACH is n, where 1≦n≦10 m, andk≦n.

Further, the second transmitter 53 is further configured to send adownlink reference signal, so that the user equipment determines,according to the received downlink reference signal, that the quantityof repetition times of the preamble sequence at the preset resourcelocation of the preset PRACH is n.

Further, the second receiver 54 is specifically configured to receive,at the n preset resource locations of the m preset radio frames in thepreset PRACH, the k preamble sequences from the user equipment.

Further, the second receiver 54 is specifically configured to receive,within n preset subframes of the m preset radio frames in the presetPRACH, the k preamble sequences from the user equipment.

As shown in FIG. 18, the base station 5 provided in this embodiment ofthe present invention further includes: a second processor 55,configured to: add up signal strength of the k preamble sequencesreceived by the second receiver 54, and perform comparison betweenadded-up signal strength of the k preamble sequences and a presetstrength threshold.

Further, the second transmitter 53 is further configured to: if thesignal strength obtained by the second processor 55 by adding up the kreceived preamble sequences is greater than or equal to the presetstrength threshold, return a response message corresponding to the kpreamble sequences to the user equipment.

According to the base station provided in this embodiment of the presentinvention, system information or a PBCH is broadcast, where the systeminformation or the PBCH includes a preset PRACH, the preset PRACHincludes m preset radio frames, and m is a positive integer; k preamblesequences are received from user equipment at n preset resourcelocations of the preset PRACH, where the k preamble sequences are sentat the n preset resource locations of the preset PRACH after the userequipment determines that a quantity of repetition times of the preamblesequence, which is used for random access, at a preset resource locationof the preset PRACH is n. By using this solution, the user equipmentsends, at the n preset resource locations of the preset PRACH, thepreamble sequence to the base station, that is, the quantity ofrepetition times of the preamble sequence sent by the user equipment tothe base station increases; therefore, signal strength of the preamblesequence received by the base station is enhanced, so that the preamblesequence can be correctly matched, thereby increasing a matchingprobability of the base station and increasing efficiency of gainingaccess to a cell by the user equipment.

As shown in FIG. 19, this embodiment of the present invention provides apreamble sequence transmission system 6, including: any user equipment 4and any base station 5 that are described above.

According to the preamble sequence transmission system provided in thisembodiment of the present invention, user equipment acquires systeminformation or a PBCH that is broadcast by a base station, where thesystem information or the PBCH includes a preset PRACH and multiplepreamble sequences, the preset PRACH includes m preset radio frames, andm is a positive integer; the user equipment determines that a quantityof repetition times of a preamble sequence, which is used for randomaccess, at a preset resource location of the preset PRACH is n, where1≦n≦10 m; and the user equipment sends, at n preset resource locationsof the preset PRACH, the preamble sequence to the base station, so thatthe base station returns, after adding up and performing matching for kreceived preamble sequences, a response message corresponding to the kpreamble sequences. By using this solution, the user equipment sends, atthe n preset resource locations of the preset PRACH, the preamblesequence to the base station, that is, the quantity of repetition timesof the preamble sequence sent by the user equipment to the base stationincreases; therefore, signal strength of the preamble sequence receivedby the base station is enhanced, so that the preamble sequence can becorrectly matched, thereby increasing a matching probability of the basestation and increasing efficiency of gaining access to a cell by theuser equipment.

The solutions in the present invention can be described in the generalcontext of executable computer instructions executed by a computer, forexample, a program unit. Generally, the program unit includes a routine,program, object, component, data structure, and the like for executing aparticular task or implementing a particular abstract data type. Thesolutions in the present invention may also be practiced in distributedcomputing environments in which tasks are performed by remote processingdevices that are connected by using a communications network. In adistributed computing environment, program units may be located in bothlocal and remote computer storage media including storage devices.

The embodiments in this specification are all described in a progressivemanner, for same or similar parts in the embodiments, mutual referencemay be made, and each embodiment focuses on a difference from otherembodiments. Especially, an apparatus embodiment is basically similar toa method embodiment, and therefore is described briefly; for relatedparts, refer to the part of description in the method embodiment. Thedescribed apparatus embodiments are merely exemplary. The unitsdescribed as separate parts may or may not be physically separate, andparts displayed as units may or may not be physical units and may belocated in one position, or may be distributed on a plurality of networkunits. Some or all of the modules may be selected according to actualrequirements to achieve the objectives of the solutions of theembodiments. A person of ordinary skill in the art may understand andimplement the embodiments of the present invention without creativeefforts.

A person of ordinary skill in the art may be aware that the exemplaryunits and algorithm steps described with reference to the embodimentsdisclosed in this specification may be implemented by electronichardware or a combination of computer software and electronic hardware.Whether the functions are performed by hardware or software depends onparticular applications and design constraint conditions of thetechnical solutions. A person skilled in the art may use differentmethods to implement the described functions for each particularapplication, but it should not be considered that the implementationgoes beyond the scope of the present invention.

It may be clearly understood by a person skilled in the art that, forthe purpose of convenient and brief description, for a detailed workingprocess of the foregoing system, apparatus, and unit, reference may bemade to a corresponding process in the foregoing method embodiments, anddetails are not described herein again.

In the several embodiments provided in the present application, itshould be understood that the disclosed system, apparatus, and methodmay be implemented in other manners. For example, the describedapparatus embodiments are merely exemplary. For example, the unitdivision is merely logical function division and may be other divisionin actual implementation. For example, a plurality of units orcomponents may be combined or integrated into another system, or somefeatures may be ignored or not performed. In addition, the displayed ordiscussed mutual couplings or direct couplings or communicationconnections may be implemented by using some interfaces. The indirectcouplings or communication connections between the apparatuses or unitsmay be implemented in electronic, mechanical, or other forms.

The units described as separate parts may or may not be physicallyseparate, and parts displayed as units may or may not be physical units,and may be located in one position or may be distributed on a pluralityof network units. Some or all of the units may be selected according toactual needs to achieve the objectives of the solutions of theembodiments.

In addition, functional units in the embodiments of the presentinvention may be integrated into one processing unit, or each of theunits may exist alone physically, or two or more units are integratedinto one unit.

When the functions are implemented in a form of a software functionalunit and sold or used as an independent product, the functions may bestored in a computer-readable storage medium. Based on such anunderstanding, the technical solutions of the present inventionessentially, or the part contributing to the prior art, or some of thetechnical solutions may be implemented in a form of a software product.The computer software product is stored in a storage medium, andincludes several instructions for instructing a computer device (whichmay be a personal computer, a server, or a network device) to performall or some of the steps of the methods described in the embodiments ofthe present invention. The foregoing storage medium includes: any mediumthat can store program code, such as a USB flash drive, a removable harddisk, a read-only memory (ROM, Read-Only Memory), a random access memory(RAM, Random Access Memory), a magnetic disk, or an optical disc.

Based on the description of the foregoing implementation manners, aperson skilled in the art may clearly understand that the presentinvention may be implemented by software in addition to necessaryuniversal hardware, where the universal hardware includes a universalintegrated circuit, a universal CPU, a universal memory, a universalcomponent, and the like; or may be implemented by dedicated hardware,where the dedicated hardware includes a dedicated integrated circuit, adedicated CPU, a dedicated memory, a dedicated component, and the like.In most circumstances, the former is a preferred implementation manner.Based on such an understanding, the technical solutions of the presentinvention essentially or the part contributing to the prior art may beimplemented in a form of a software product. The software product isstored in a readable storage medium, such as a floppy disk, a hard diskor an optical disc of a computer, and includes several instructions forinstructing a computer device (which may be a personal computer, aserver, or a network device) to perform the methods described in theembodiments of the present invention.

The foregoing descriptions are merely specific implementation manners ofthe present invention, but are not intended to limit the protectionscope of the present invention. Any variation or replacement readilyfigured out by a person skilled in the art within the technical scopedisclosed in the present invention shall fall within the protectionscope of the present invention. Therefore, the protection scope of thepresent invention shall be subject to the protection scope of theclaims.

What is claimed is:
 1. A method, comprising: acquiring systeminformation or a physical broadcast channel (PBCH) that is broadcast bya base station, wherein the system information or the PBCH comprises apreset physical random access channel (PRACH) that comprises m presetradio frames and a number of repetition times of a preamble sequence n,which is used for random access, wherein m is a positive integer, and1≦n≦10 m; and sending the preamble sequence to the base station, thepreamble sequence being sent at n preset resource locations of thepreset PRACH, where the preamble sequence is a format of 1 ms, or aformat of 2 ms, or a format of 3 ms.
 2. The method according to claim 1,wherein sending the preamble sequence to the base station comprisessending, within n preset subframes of the m preset radio frames in thepreset PRACH, the preamble sequence to the base station.
 3. The methodaccording to claim 1, wherein, after sending the preamble sequence, themethod further comprises sending the preamble sequence to the basestation when no response message is received from the base station, thepreamble sequence being sent at p preset resource locations of thepreset PRACH, wherein p>n.
 4. A user equipment, comprising: a receiver,configured to receive system information or a physical broadcast channel(PBCH) that is broadcast by a base station, wherein the systeminformation or the PBCH comprises a preset physical random accesschannel (PRACH) that comprises m preset radio frames and a number ofrepetition times of a preamble sequence n, which is used for randomaccess, m being a positive integer, wherein 1≦n≦10 m; and a transmitter,configured to transmit, at n preset resource locations of the presetPRACH, the preamble sequence to the base station, where the preamblesequence is a format of 1 ms, or a format of 2 ms, or a format of 3 ms.5. The user equipment according to claim 4, wherein the transmitter isconfigured to transmit, within n preset subframes of the m preset radioframes in the preset PRACH, the preamble sequence to the base station.6. The user equipment according to claim 4, wherein after transmitting,at the n preset resource locations of the preset PRACH, the preamblesequence to the base station, the transmitter is further configured to:when no response message is received by the receiver from the basestation, transmit, at p preset resource locations of the preset PRACH,the preamble sequence to the base station, wherein p>n.
 7. A basestation, comprising: a transmitter, configured to broadcast systeminformation or a physical broadcast channel (PBCH), wherein the systeminformation or the PBCH comprises a preset physical random accesschannel (PRACH), the preset PRACH comprises m preset radio frames and anumber of repetition times of a preamble sequence n, which is used forrandom access, wherein m is a positive integer, and 1≦n≦10 m; areceiver, configured to receive, at n preset resource locations of thepreset PRACH, k preamble sequences from user equipment, wherein the kpreamble sequences are sent at the n preset resource locations of thepreset PRACH, wherein k≦n, and the preamble sequence is a format of 1ms, or a format of 2 ms, or a format of 3 ms; and a processor,configured to: add signal strengths of received k preamble sequences;and determine whether to return a response message corresponding to thepreamble sequence to the user equipment according to the added signalstrengths.
 8. The base station according to claim 7, the receiver isconfigured to receive, within n preset subframes of the m preset radioframes in the preset PRACH, the k preamble sequences from the userequipment.